大约有 47,000 项符合查询结果（耗时：0.0343秒） [XML]
Which machine learning classifier to choose, in general? [closed]
...
Model selection using cross validation may be what you need.
Cross validation
What you do is simply to split your dataset into k non-overlapping subsets (folds), train a model using k-1 folds and predict its performance using the...
Directive isolate scope with ng-repeat scope in AngularJS
...moved:
<li ng-repeat="name in names"
ng-class="{ active: $index == selected }"
ng-click="selected = $index">
{{$index}}: {{name.first}} {{name.last}}
</li>
Here is a JSFiddle demonstrating that it won't work. You get the exact same results as in your directive.
Why doesn'...
How do I kill all the processes in Mysql “show processlist”?
...peration saves time. Do it in MySql itself:
Run these commands
mysql> select concat('KILL ',id,';') from information_schema.processlist
where user='root' and time > 200 into outfile '/tmp/a.txt';
mysql> source /tmp/a.txt;
Reference
---------edit------------
if you do not want to sto...
String.Join method that ignores empty strings?
... simpler, since you can do it in SQL directly:
PostgreSQL & MySQL:
SELECT
concat_ws(' / '
, NULLIF(searchTerm1, '')
, NULLIF(searchTerm2, '')
, NULLIF(searchTerm3, '')
, NULLIF(searchTerm4, '')
) AS RPT_SearchTerms;
And even with the glorious MS-SQ...
Query to count the number of tables I have in MySQL
...
SELECT COUNT(*) FROM information_schema.tables WHERE table_schema = 'dbName';
Source
This is mine:
USE databasename;
SHOW TABLES;
SELECT FOUND_ROWS();
...
Multiple “order by” in LINQ
...ow in _db.Movies
orderby row.Category, row.Name
select row;
[EDIT to address comment] To control the sort order, use the keywords ascending (which is the default and therefore not particularly useful) or descending, like so:
var movies = from row in _db.Movies
...
Query for array elements inside JSON type
...src":"bar.png"}]
, "background":"background.png"}'::json)
)
SELECT *
FROM reports r, json_array_elements(r.data#>'{objects}') obj
WHERE obj->>'src' = 'foo.png';
The CTE (WITH query) just substitutes for a table reports.
Or, equivalent for just a single level of nesting:
SE...
Possible to perform cross-database queries with PostgreSQL?
... executes a query in a remote database
dblink executes a query (usually a SELECT, but it can be any SQL
statement that returns rows) in a remote database.
When two text arguments are given, the first one is first looked up as
a persistent connection's name; if found, the command is executed on
that...
How to highlight cell if value duplicate in same column for google spreadsheet?
...
Try this:
Select the whole column
Click Format
Click Conditional formatting
Click Add another rule (or edit the existing/default one)
Set Format cells if to: Custom formula is
Set value to: =countif(A:A,A1)>1 (or change A to your ch...
How do I change Eclipse to use spaces instead of tabs?
...dow » Preferences
Expand Web » HTML Files
Click Editor
Under Formatting, select the Indent using spaces radio button
Click OK to apply the changes.
CSS
Follow the same instructions for HTML, but select CSS Files instead of HTML Files.
JSP
By default, JSP files follow the formatting preference...